Remote triggered x-ray image capture device with gamma ray detector

ABSTRACT

Systems and methods are presented herein for generating an X-ray image where the X-ray image generator has no electrical connection with an X-ray source that generates the X-rays. In an exemplary embodiment a gamma detector is positioned behind an x-ray permeable mirror within an X-ray capture device. When the gamma ray detector senses gamma radiation over a threshold level, a camera, positioned outside of the X-ray path, begins capturing an image of the X-ray. The image is then discarded if an X-ray image profile is not then detected by the gamma detector within a period of time. Such an X-ray image profile may be detected if two or more X-ray pulses with similar intensity and duration are detected within a set period of time. If an X-ray image profile is detected, then the camera continues recording the X-ray image for a predetermined time.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of U.S. patent application Ser. No.11/317,462, filed Dec. 22, 2005, and entitled REMOTE TRIGGERED X-RAYCAPTURE DEVICE, incorporated herein by reference, and acontinuation-in-part of U.S. patent application Ser. No. 11/455,141,filed Jun. 15, 2006, and entitled REMOTE TRIGGERED X-RAY CAPTURE DEVICE,incorporated herein by reference. This application claims the benefit ofU.S. Provisional Application No. 60/934,805, filed Jun. 14, 2007, whichis incorporated by reference herein in its entirety.

BACKGROUND

X-ray images can be taken with film in traditional radiography, they canbe digitally generated using imaging plates in a process called computedradiography, and digital images can be generated directly from theX-rays themselves in a process called direct digital radiography. Eachof these systems has its drawbacks. When film is used to process X-rays,the film must be purchased for each X-ray, and the film must bedeveloped in a process that takes somewhere around 90 seconds to 5minutes per shot. A patient must wait for the entire developing time todetermine if an image is clear or if a retake is needed. Furthermore,processing the films requires that noxious chemicals be used and stored,and disposed.

Computed radiography removes the film from the X-ray process, replacingit instead with a digital imaging plate the same dimensions as the filmand placed in the same location. After the imaging plate is exposed tothe X-rays, it is placed in an imaging reader, which takes about 90seconds to generate the digital image. This delay, while notinsurmountable when human adults are having their X-rays taken, is muchmore problematic when the X-ray subject is a small child or an animalwhich does not understand the need to remain quiet and positioned.Furthermore, the imaging plate is expensive and fragile, an expensiveimaging reader must also be used, and generating the digital X-ray imagetakes roughly the same time as in conventional radiography.

Direct digital radiography uses an imaging sensor in the path of theX-rays to take a direct digital X-ray, which can then immediately bedisplayed on a computer screen and saved in a digital file for easyreference. However, it is difficult to adequately shield the imagingsensor from the X-rays, requiring that this expensive piece of equipmentbe regularly replaced. Moreover, there must be an electrical connectionbetween the imaging sensor and the X-ray generator, making retrofittingexisting X-ray equipment difficult or impossible.

SUMMARY

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription section. This summary is not intended to identify keyfeatures or essential features of the claimed subject matter, nor is itintended to be used as an aid in determining the scope of the claimedsubject matter.

In an embodiment, a system is provided which comprises an X-ray to lightconverter which converts an x-ray image to a light image; a mirror boxwith a camera opening; a first and second mirror mounted within themirror box; and a camera mounted substantially outside of the mirror boxabove the camera opening such that the camera is out the path of thex-rays.

The mirror box is constructed with a first mirror at substantially a 45degree angle from the camera aperture and a second mirror atsubstantially an 85 degree angle to the first mirror. This creates afolded light such that an image traveling along the folded light path isreflected by the mirrors, a first segment of the light image crossing asecond segment of the light image at least twice, the mirrorssubstantially focusing the light image on the camera. The mirror boxdissipates sufficient heat that no other heat-dissipation device isrequired for the light.

A photon detector, such as a light detector or a gamma ray detector,such as a proportional counter, can also be included which is mountedsubstantially outside of the mirror box behind the first mirror. Thefirst mirror allows x-rays to pass through an aperture in the mirror boxcovered by the mirror, striking the gamma ray detector and therebytriggering the camera.

Additional features and advantages will become apparent from thefollowing detailed description of illustrated embodiments, whichproceeds with reference to accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is an illustration of several aspects of a remote-triggeredX-ray capture device including aspects of the enclosure unit inconjunction with which described embodiments may be implemented.

FIG. 1B is an illustration of several aspects of a remote-triggeredX-ray capture device which builds on aspects shown in FIG. 1A inconjunction with which described embodiments may be implemented.

FIG. 2 is an illustration of several aspects of a remote-triggered X-rayimage capture device which builds on aspects shown in FIG. 1 inconjunction with which described exemplary embodiments may beimplemented.

FIG. 3 is an illustration of several aspects of a remote-triggered X-rayimage capture device including light paths in conjunction with whichdescribed exemplary embodiments may be implemented.

FIG. 4 is a functional block diagram illustrating an embodiment of anexample system for capturing X-ray images in conjunction with whichdescribed exemplary embodiments may be implemented.

FIG. 5 is an operational flow diagram illustrating a process forcapturing X-ray images in conjunction with which described exemplaryembodiments may be implemented.

FIG. 6 is an operational flow diagram illustrating a process fordisplaying an X-ray image.

FIGS. 7A-C are exemplary schematic diagrams showing the position ofX-ray data within a captured X-ray image.

FIG. 8 is a block diagram showing an exemplary system for displaying anX-ray image.

FIG. 9 is an operational flow diagram illustrating a process forlocating an x-ray image within a larger captured image.

FIG. 10 is an operational flow diagram which is a continuation of theprocess for locating an x-ray image within a larger captured imageillustrated in FIG. 9.

FIG. 11 is a block diagram illustrating an exemplary system fordisplaying x-ray image data.

FIGS. 12A and B are X-ray images before and after applyingparameterization.

FIG. 13A is a perspective view of an embodiment of the x-ray deviceenclosure unit.

FIG. 13B is a plan view of the embodiment of the x-ray device shown inFIG. 13A.

FIG. 14 is an exploded perspective view of the x-ray device enclosureunit of FIG. 13A.

FIG. 15 is another exploded perspective view of the X-ray deviceenclosure unit of FIG. 13A.

FIG. 16A is an elevation view of another embodiment of an X-ray deviceenclosure unit.

FIG. 16B is a cutaway view of the X-ray device enclosure unit of FIG.16A.

FIG. 16C is a cutaway view of the elevation of FIG. 16A showing anexemplary light path.

FIG. 17 is a block diagram of a suitable computing environment inconjunction with which described exemplary embodiments may beimplemented.

FIG. 18 is an operational flow diagram illustrating a process forchoosing whether to discard or save an image after gamma radiation hasbeen detected.

FIG. 19 is an exemplary chart showing gamma radiation output from anX-ray image.

FIG. 20 is a is an operational flow diagram further illustrating theprocess shown in FIG. 18.

FIG. 21 is a is an operational flow diagram further illustrating theprocess for determining if a pulse has been received as shown in FIG.20.

DETAILED DESCRIPTION

The present application relates to technologies for remote-triggeredX-ray devices. Described embodiments implement one or more of thedescribed technologies.

Various alternatives to the implementations described herein arepossible. For example, embodiments described with reference to flowchartdiagrams can be altered by changing the ordering of stages shown in theflowcharts, by repeating or omitting certain stages, etc. As anotherexample, although some implementations are described with reference tospecific devices, such as cameras and screens which transform X-raysinto light; other devices with the same functionality also can be used.

The various technologies can be used in combination or independently.Different embodiments implement one or more of the describedtechnologies. Some technologies described herein can be used inconjunction with a computer; such a computer could be a desktopcomputer, a portable computer, a handheld computer, a wearable computingdevice, a Personal Digital Assistant (PDA), or an intelligent cellphone.

I. Overview

With reference to FIGS. 1A and 1B, systems and methods are presentedherein for creating a remote-triggered X-ray device 100. The device isdesigned to be used with existing X-ray generators, as it does notrequire an electrical connection between the existing X-ray machine andthe direct digital radiography recording device. When an X-ray generator102 is activated, X-rays 105 are directed towards a screen 110. X-raysare electromagnetic radiation with a wavelength between 10 nanometersand 100 picometers. This corresponds to frequencies between 30 PHz and 3EHz. X-ray wavelengths overlap those of Gamma rays; Gamma rays aregenerated by transitions within the atomic nucleus, while X-rays aregenerated by energetic electron processes. For the purposes of theseembodiments, all radiation with wavelengths between 10 nm and 100 pm, nomatter what the source, should be considered X-rays.

The screen 110 transforms X-rays 105 into light 115, which may befluorescent light. In some embodiments, the light may be in the visible,the infrared, or the ultraviolet spectrum, or some combination thereof.Screens, such as the screen 110 are intensifying screens, and generallycontain, among other ingredients, a layer of phosphor crystals. When anX-ray photon strikes a phosphor crystal, many light photons are emitted,which can then be used to generate an X-ray image of a specimen. Twomajor types of phosphors used to create intensifying screens for usewith envisioned embodiments are calcium tungstate (CaWO₄) and variousrare earths. Among the rare earths, Gadolinium Oxysulfide andThallium-doped Cesium Iodide are among the substances suitable forbuilding an intensifying screen. However, other substances that convertX-rays to light, such as metal screens, are also envisioned to be used.

The screen 110, 205 is mounted on the top of the beam enclosure unit120. This beam enclosure unit 120, in an exemplary embodiment, isinstalled under a table top. A variety of mounting devices adapted toeach type of table manufactured are expected to be used in theinstallation. When an embodiment is used in a veterinary setting, thosemounting in common use in veterinary medicine are used. The beamenclosure unit 120 should be installed such that the system weight issupported and such that an X-ray beam is appropriately aligned duringexposure. The support mechanism can allow freedom of motion when anX-ray support tower (not shown) is moved toward either end of the tablethat the beam enclosure unit 120 is installed underneath. In anotherembodiment, the beam enclosure unit 120 is installed without a tablepresent.

The aperture of the beam enclosure unit 120 through which the X-rays 105enter measures, in exemplary embodiments, may be any size, but sizessuitable for a wide variety of X-ray technologies, such as intra-oralX-rays for dentists, as well as X-rays suitable for large animals,extremely large X-rays taken for non-destructive testing are allenvisioned. For example and not limitation, aperture ranges from 12mm×16 mm (or smaller) up to 17″×17″ or larger are envisioned. Alight-tight cover is also included (not shown) which also may act assupport for the screen 110. The screen 110 may be bonded to thelight-tight cover. The light-tight cover may be any low molecular weightmaterial such as aluminum, carbon fiber or even cardboard to minimizeX-ray absorption. The light-tight cover can be bolted around itsperimeter to the beam enclosure 120 with tamper-proof screws.

Turning to FIGS. 2 and 3, and with continuing reference to FIG. 1, thelight 115 is captured by an accumulator 220, which, in an exemplaryembodiment, is designed to minimize quantum efficiency loss and providean optically flat field. A small amount of adjustment of the light raysentering the accumulator 220 may be provided by the accumulator 220.

A light measuring device such as a camera 230 is placed in an enclosure215 just behind the accumulator 220. Shielding 210 protects the camera230 from the X-rays 105. Because of the location of the shielding 210 inrelation to the X-rays 105 in the beam enclosure unit 120, steel can beused for the shielding rather than the more common lead, as the camera230 is out of the direct path of the X-rays. In another exemplaryembodiment, lead is used for the shielding. Additional shielding may beplaced along other areas where X-rays may penetrate 225, 235. Thedangers of X-ray radiation on living tissue is well-known. X-rays arealso destructive of sensitive equipment. For example, X-ray exposure cangreatly shorten the working life of a camera used to take an X-ray.Shielding the camera 230, as is done here, both by using traditionalshielding 210, 225, 235, and by placing the camera 230 out of the directpath of the X-rays, can lead to a much longer camera life, and cangreatly reduce the amount of maintenance needed on the X-ray device.

A mirror 240 is also included as part of the beam enclosure 120, in anexemplary embodiment. An optional accumulator 220 is arranged in frontof the camera 230. The mirror 240 reflects the light 115 from the screen110 such that substantially the entire image can be captured by thecamera 230. In an exemplary embodiment, the reflected light path isshown at 310, 315. It can be seen that the entire aperture of the beamenclosure unit 120 through which the X-rays 105 enter can effectively be“seen” by the camera 230 through the image reflected in the mirror 240.Thus, when the camera 230 is triggered, the camera 230 capturessubstantially the entire X-ray image (as translated into light). Themirror 240, in an exemplary embodiment, is mounted at a 45-degree angle,though other angles of mounting are envisioned. Additionally, the mirror240 may be enhanced by surface preparation to provide additional lightreflection when mounted between 43 degrees and 47 degrees to theincident light beam. The mirror 240 may reflect in excess of 97.5% ofthe available light, and may be aluminum-enhanced, and micro- orpico-ground.

In an exemplary embodiment, there is no connection between the X-raysource 100, shown in FIGS. 1A and 1B and the remote-triggered X-raydevice. This allows the X-ray device to be easily retrofitted toexisting X-ray sources, as there is no need for an electrical connectionbetween the existing X-ray source and this device. Therefore, wiringdiagrams need not be consulted, for example. This allows existing X-raysources, whose wiring may have been lost, to still be retrofitted withminimum difficulty. In systems whose wiring is known, the expense andtime of wiring the two devices together is eliminated. Further, anentire category of timing problems between the systems is alsoeliminated.

With reference to FIG. 3, a photon detector 320 is provided whichtriggers substantially at the exact moment that the visible light rays115 are available to be captured by the camera 230. The location of thephoton detector 320 in FIG. 3 is for illustrative purposes only; it canbe placed anywhere within the beam enclosure unit 120 that isconvenient. It may also be placed outside the beam enclosure unit 120 ifby such placement it can still trigger the camera 230 at the time ofX-ray generation without being integrated into the circuitry of the hostX-ray source. When the camera 230 is triggered by the photon detector320, it creates a digital image representative of the X-rays. As shownin FIG. 1B, this digital image can then be transferred through a link125 to a computer 130, which then processes the image and displays it ona computer screen 135. In an exemplary embodiment, the system is usedprimarily in a veterinary setting.

II. Exemplary System Embodiment

Referring to FIG. 4, a block diagram of a system for capturing X-rayimages 400 shows an exemplary embodiment of the systems discussedherein.

The system for capturing X-ray images 400 consists of a screen 402,which converts X-ray photons to light photons. Generally, the screencontains a material, among other components, which, when struck by anX-ray photon, generates light photons. Inorganic salts, also known asphosphors, are among the materials that are suitable to generate lightphotons when struck by an X-ray photon. If an inorganic salt is used, itwill generate fluorescent light. Only a portion of the X-rays will beabsorbed by the screen, causing light photons to be emitted. Forexample, if calcium tungstate is used, approximately 20 to 40 percent ofthe X-ray photons will be absorbed; the bulk of the rest will passthrough the screen into the beam enclosure unit 120. In comparison, rareearth screens absorb approximately 60 percent of the X-ray photons.Furthermore, the efficiency of calcium tungstate screens at convertingX-rays into light is only about one-third to one-fourth that of rareearth screens.

When an X-ray photon hits a phosphor crystal, the phosphor crystalabsorbs the X-ray and emits a number of light photons. The size of thephosphor layer and the size of the individual phosphor crystals are someof the factors that determine the level of detail in the eventual X-rayimage. The larger the individual crystal and the thicker the phosphorlayer, the more spread-out the individual light photons are that aregenerated by the crystal. The image detail is degraded by the size ofthe light spread, as the same amount of information is smeared over alarger area. These considerations can be taken into account whendetermining the optimal material for a given screen.

The system also contains a mirror 406. The light rays generated by thescreen 402, continue on the same path as that of the initial X-rays thatgenerated the light. The mirror 406 reflects the light rays that strikeit at such an angle that the light-measuring device 408 is focused onthe screen 402 such that when the light-measuring device 408 istriggered, a view of substantially the entire screen is captured. Asshown, the image path from the light measuring device 408 is folded,such that the light rays strike the mirror 406 and are bent such that atleast some of the light rays cross paths on their way to the screen. Theillustrated embodiment shows the rays bending once; other embodimentscan employ image paths that bend the rays multiple times. In anexemplary embodiment, the mirror 406 is placed at a 45 degree angle tothe screen 402. In alternate embodiments, the mirror is positioned suchthat a portion of the screen 402 is captured. Optionally, an accumulator404 is used to at least partially focus the light on the light-measuringdevice 408. This light-measuring device 408, in an exemplary embodiment,is a charge-coupled device 409. In an alternate embodiment, acomplementary metal oxide semiconductor (CMOS) device 410 is used as thelight-measuring device 408. An exemplary embodiment employs more thanone light-measuring device.

When the light-measuring device 408 is triggered, each pixel that makesup a light-measuring array in either the charge-coupled device 409 orthe CMOS device 410 is struck by some number of light photons, which arethen converted to electrons. The number of electrons in each pixel isconsidered the pixel's charge. A converter 412 then converts the chargeinto a digital value. Each of the digital values is then associated witha specific gray-scale value, in an exemplary embodiment, to form adetailed black and white image.

In another embodiment, the light-measuring device 408 records the imagesin color, with each digital value associated with a color, using somecolor space to assign specific values to the pixels. Examples ofexemplary color spaces known to those in the art that could be used inexemplary embodiments are RGB, CNY, CMYK, HSV, HLS, and so on.

In an exemplary embodiment, a large-format charge-coupled device has an11 megapixel grid, which provides up to 16 bits of grey depth in eachpixel, resulting in over 65,000 shades of gray being available to beused in the eventual image. In another exemplary embodiment, a 4megapixel grid is used, which provides two line pairs per millimeterresolution on the final image.

As there is no direct electrical connection between the system forcapturing X-ray images 400 and the source of the X-rays 422, the systemitself determines when to trigger the light-measuring device 408. Itdoes this using a photon detection device 414, which, when it registerseither X-rays or light, sends an activation message to thelight-measuring device 408 telling it to “snap the picture.” Someembodiments may only trigger the light-measuring device 408 when anumber of photons over a background threshold amount are detected. IfX-rays are detected, an exemplary embodiment uses an ionization chamberas the photon detection device 414. In some embodiments, a gamma raydetector is used for the photon-detector device, such as a proportionaldetector, which detects the amount as well as the presence of gammarays.

The digital image in the converter 412, which represents an X-ray of asubject, is transferred to a computer 418 using a link 416. This linkmay be a network connection. If so, it may be a wireless networkconnection. Once the computer 418 has the image, it processes it to makeit clear and readable on a video monitor such as a computer screen, andthen displays it on the video monitor 420.

III. Exemplary Method for Creating X-ray Images

FIG. 5 is an operational flow diagram illustrating a process forcreating X-ray images 500. The process begins at process block 502,where X-rays are converted into light. When an X-ray photon hits aphosphor crystal, the phosphor crystal absorbs the X-ray and emits anumber of light photons. The size of the phosphor layer and the size ofthe individual phosphor crystals are some of the factors that determinethe level of detail in the eventual X-ray image. The larger theindividual crystal and the thicker the phosphor layer, the morespread-out the individual light photons are that are generated by thecrystal. The image detail is degraded by the size of the light spread,as the same amount of information is smeared over a larger area. Theseconsiderations can be taken into account when determining the optimalmaterial for a given screen.

The process continues at process block 503, where a photon sensor isused to detect whether X-rays or light rays are present. At processblock 504, a mirror is used to reflect the light used by alight-measuring device such that essentially all of the light convertedby X-rays can be “seen” by the light-measuring device, even if thelight-measuring device is out of the direct path of the X-rays.

The process 500 is independent from an X-ray source process whichcreates the X-rays, so a method internal to process 500 must be used todetermine when an X-ray machine has taken an X-ray. When X-rays or lightrays are detected at process block 506, a light-image sensor istriggered, which generates an image corresponding to the X-ray. As haspreviously been detailed, this light image sensor may be acharge-coupled device, a CMOS device, or another device suitable fortranslating light energy into digital output.

At process block 508, the image is transferred to a computer. Thetransfer may take place through a network connection. The network may bea local or wide-area network. Furthermore, the network may be wired orthe image may travel using a wireless network. In exemplary embodiments,the image is sent through a wireless connection to a communicationdevice, such as a laptop or a portable communication device such as aPDA or an internet-enabled cell phone.

At process block 510, the image, after it has been processed by thecomputer, is displayed on a computer screen. The processing comprisesturning the digital representation into an image that can be viewed on ascreen, and may comprise certain modifications to the image, as areknown to those of skill in the art. For example, if the image wasinitially exposed for too long and is too dark, an algorithm may beemployed which “lightens” the image, making it easier to read. In someembodiments, an algorithm may be employed on some images to sharpenspecific areas, increasing contrast over what would otherwise be seen. Avariety of other visualization techniques may be used as well, such asthick-slab rendering, shaded volume rendering, shaded surface display,multi-planar reformatting, flexible clipping, maximum intensityprojection, perspective viewing, and the like.

Processing may be provided which allows the image to be transferred to adifferent system, or which stores the image in a standard format, suchas DICOM, CMP, PNG, JPEG, TIFF, GIF, or other widely-available format.Some embodiments may include algorithms which store the images in aproprietary format, the proprietary format being a format used by asingle vendor or a limited number of vendors. Other processing, as knownto those of skill in the art, is also envisioned.

IV. Exemplary Method to Display an X-ray Image

FIG. 6 shows an exemplary method 600 to display an X-ray image. TheX-ray image to be displayed may be of an adult human or child, or of ananimal, such as would be seen in a veterinary practice. The animal maybe very large, such as a horse, or much smaller, such as a ferret. At605 the X-ray image is captured. The capture may be performed by asystem such as that shown at 400 in FIG. 4. In some embodiments, ascreen such as that shown at 110 in FIG. 1 may be used to transform thex-rays into light rays prior to the x-ray image being captured, using amethod that is sometimes called indirect conversion. In otherembodiments, no such screen is used—that is, the x-rays are directlyconverted into the x-ray image, which may be a digital image. At 610,the captured image is located. The exemplary method 600 may be performedby a system, such as that shown at 400 wherein the X-ray source 422 isunattached to the system for capturing x-ray images 400. In such a case,the X-ray data must be cropped out of larger image with unexposed edges.At 675, the located X-ray data is displayed.

V. Exemplary Schematic Diagrams of Exemplary X-Ray Images

FIGS. 7A-C are exemplary schematic diagrams showing the position ofX-ray data within a captured X-ray image. A captured X-ray image 700 isshown in FIG. 7A. The image is composed of the actual X-ray image data710 and junk data values 705 which represent unexposed portions of theimage. FIG. 7B shows a reduced-resolution x-ray image 752. Also shownare corners 755 and 760, which can be located to determine the exactlocation of the X-ray image data 710. FIG. 7C shows the angulation 780of a captured X-ray image 775.

VI. Exemplary System to Display an X-Ray Image

FIG. 8 is a block diagram 800 showing an exemplary system for displayingan X-ray image. At 805, an X-ray image is captured. This image may becaptured using a system, such as the system 400 wherein the X-ray source422 has no electrical connection with the X-ray image capturer 400. Thecapturing itself may be done by a charge-coupled device or a CMOSsensor, or a different sort of light- or x-ray sensitive device. Forexample, an exemplary embodiment may use an electronic array made atpartially from, for example, amorphous selenium, which converts x-raysdirectly to an electric charge. Another exemplary embodiment uses anelectronic array made at least partially of amorphous silicon. The imagemay be captured as a digital representation, and may be represented as agrayscale digital image. In at least some embodiments, the image iscaptured as a combination of colors other than black and white. In agrayscale digital image, the image is captured as a grid of pixels, eachpixel having a value representing a shade of gray. Possible digitalrepresentations for the original capture comprise 8 bit, 12 bit, 16 bit,or a different resolution.

In an 8 bit grayscale image, the image is generally captured as 256shades of gray. In a 12 bit grayscale image, there are 4096 shades ofgray, with, in some conventions, 0 being black, and 4095 representingwhite. In a 16 bit grayscale image, there are 65,536 distinct shades ofgray. A monochromatic image may contain only black and white, and may beconsidered a 1-bit grayscale or a binary image.

The captured image is shown at 807. The actual x-ray image data may nottake up the entire captured X-ray image, that is, there may be darkareas without data along the edges of the picture, as shown at 705 inFIG. 7A. At 830, the captured image 807 is located within the largerimage generated when the X-ray image is captured. This creates a locatedimage 837. At 875, a displayer displays the located image 837. The imagemay be displayed, for example, on a display 135 as shown in FIG. 1B.Even though the exact size and angulation of the X-ray data may not beknown, the data itself is expected to be rectangular. Therefore, someembodiments include squaring off the edges that have been located; thatis finding data points along at least two edges and the connecting thepoints in such a way that a rectangular image is determined.

In some embodiments, the displayer displays an image prior to the imagebeing located 837. This can be done to show that a captured image hasbeen received, to facilitate placement of the subject on the X-ray, andthe like.

VII. Exemplary Method to Locate a Captured Image

FIG. 9 at 900 shows an exemplary method for locating an x-ray imagewithin a larger captured image. The method 900 can be performed, forexample, by the captured image locator 830 shown in FIG. 8. It isimportant that only the image itself be captured, as the processing doneto the x-ray image is such that junk data values (values incorporatedinto the image that should have been cropped) can throw off processingthat is done to filter and otherwise enhance the image. At 907, acaptured X-ray image is received. At 910, the captured image is resolvedinto an image with lesser resolution.

For example, the original captured image could be a 12-bit grayscaleimage, with 4096 possible values at each pixel location. These valuescould be reduced to a 1-bit monochromatic image, that is, two valuesonly (typically but not necessarily black and white) using a variety ofmethods known to those of ordinary skill in the art. At 915, a firstpoint in the image is located. When an X-ray image does not take up theentire digital representation, such as may happen when the X-raygenerator is misaligned with a beam enclosure unit 120 (FIG. 1) theareas that weren't exposed will be black, or close to it, as opposed tothe X-ray itself, which will have a much broader range of grayscalevalues. Resolving the original gray-scale representation to a lowerresolution image has the purpose of making the differences between thedata and the unexposed edges clearer.

In some instances, the grayscales from black to the middle value may beresolved to black, with the rest of the grayscale images resolved towhite. For example, in a 12-bit grayscale image with 4096 totalgrayscales, the values 0 to 2047 could be mapped to 0, while the values2048 to 4095 could be mapped to white. In other instances, differentmappings may be chosen, such that, for example, the lighter colors arefavored. In such an instance, more values could be mapped to white—forexample and not limitation, the values 1500-4095 could be mapped towhite, with the rest mapped to black. In yet other embodiments, thelower values are mapped to white, while the higher values are mapped toblack, etc. This should give the result that the unexposed film isresolved to black (or the shade chosen) and the x-ray data itself isresolved, essentially, to white (or the shade chosen).

Generally, the actual anatomy that appears on the x-ray after theresolving 910 will be white (or the chosen color), but there may bevalid areas around the actual x-ray image which are black, but whichwere exposed and as such are a part of the x-ray. For example, in thex-ray image 710 (FIG. 7A) the area below the animal belly marked withthe arrow is black, even though this is a legitimate portion of thex-ray image, as opposed to the unexposed edges 705. For example, thearea 758 (FIG. 7B) represents a similar area to that marked with thewhite arrow (FIG. 7A) prior to the resolving step 910, that is, an areawhich, although part of the x-ray data, appears the same as theunexposed film as there is no corresponding animal structure at thatlocation. After the resolving step 910, it has resolved to black, eventhough it is within the located x-ray image 837 (FIG. 8).

In an exemplary embodiment, more values than just black and white arechosen for the lower resolution image, for example, the image may beresolved to a two-bit grayscale image with four values.

At 915, a point within the x-ray data itself is located. The pointsoutside the X-ray data itself 752 (FIG. 7B) are themselves black, in theillustrated embodiment. The data 754 (FIG. 7B) itself in this embodimentis expected to be white. So, locating a point within the x-ray data isequivalent to finding the first white point 755 along an axis of thecaptured x-ray image 750. In some embodiments, as the exact location ofthe image is not known, some point along axis may be first located, andthen, using that point, the “corner” 755 is located. A trackingalgorithm may be used to locate a specific point, and/or the corner, oranother method may be used.

Once a first point is located, then a second data point 760 is located,as shown at process step 920. This point may be discovered by reversingthe process used to find the first point. That is, if a point wasdiscovered by looking along the x and y axes, this point could bediscovered along the −x and −y axes. In some embodiments, another“corner” is located. That is, the point itself is white (in theexemplary embodiment) and the next points along both the x and y axesare black.

Once the two points are located, then the boundaries of the x-ray imagedata are determined 925.

Due to the vagaries of x-ray data, the point located may not be at theedge of the data, rather, it may be located in an area such as the area758 which appears to be unexposed, but actually is just a legitimatedark portion of the picture. Several methods may be used to protectagainst such an image being mistakenly truncated. For example, twoperpendicular edges of the data may be plotted, with the edges thenextended to produce a reasonable representation of a corner. The entireedge, in some embodiments, is not plotted, rather enough data points arediscovered to extrapolate an edge. Once an edge is extrapolated ordetermined, the angulation of the x-ray data can be determined. Thex-ray picture may not be correctly aligned with the camera, such thatthe picture is at an angle, as can be seen at 775 in FIG. 7C. In someembodiments, angle 780 that the x-ray data is off true is used todetermine the boundaries of the x-ray data 925.

At 930, the determined boundaries are used to locate the boundaries ofthe actual x-ray image 710 producing a located x-ray image 1037 (FIG.10).

Method 1000 at FIG. 10 is a continuation of the method shown in FIG. 9.The located x-ray image 1037, in some embodiments, has a buffer appliedaround the border 1040. This buffer may be a percentage of the totalimage, such as 1/1000^(th) of the image, or a set number of pixels, suchas 30. In another exemplary embodiment, the size of the buffer dependson the angulation of the image, so that pictures with a higherangulation are given a bigger buffer.

At 1045, parameterization is determined for the x-ray image. Images areoften displayed using only a subset of the possible grayscales that makeup the original image. For example, often 256 shades are chosen; anumber that correlates with the number of colors a human can easilydistinguish and with the resolution of certain computer monitors. Aparameterization determines how to apply digital high frequency, lowfrequency, and band pass algorithms to the original shades in apredetermined amount to produce a picture with greater clarity than theoriginal x-ray image. For example, FIG. 12A at 1200 shows an x-ray imageof a dog's torso prior to parameterization, and FIG. 12B shows the samex-ray image after it has been filtered using an appropriateparameterization. The image is much clearer, with specific bones andportions of the soft tissue now visible.

Due to the large differences in bone density, bone placement, bonethickness, location, tissue structure, etc., between different types ofanimals and even between different breeds of the same species (Chihuahuax-rays may require different parameterization than Great Dane x-rays),better results are produced by having parameterization based on avariety of factors. For example, the parameterization can be based, atleast in part, on one or more of the following factors: the species ofthe animal whose x-ray is being taken 1050, the specific body part 1055,the view 1060, the thickness of the bone being x-rayed, and the energysetting 1065 that is being used.

At 1070, the parameterization chosen is used to filter the located,buffered, x-ray image. In some embodiments a separate filter is appliedprior to the parameterization 1070. At 1075, the filtered image isdisplayed. The display may be on a local computer screen, such as thedisplay 135 in FIG. 1B or may be displayed at a remote location afterhaving been transferred through a network link.

VIII. Exemplary System for Generating X-Ray Image Data

FIG. 11 shows an exemplary system for displaying x-ray image data, suchas the data generated at 506 in FIG. 5. The system comprises acharge-coupled device 1105 for taking a digital picture of an x-ray, thex-ray rays having been transformed into light rays, as is shown in FIG.1A and the associated text. The system further comprises a network 1115,which is operable to transfer the picture from the charge-coupled deviceto a computer system 1120, which may be a remote computer system. Thenetwork 1115, which may be wireless, allows the x-ray to be transferredto the computer system 1120. The network 115 may also comprise a simplecable transfer from the charge coupled device 1105 to the computersystem 1120.

The computer system 1120 comprises a resolution modifier, which canchange the resolution of the picture from, for example, a 16 bitgrayscale image to a 1 bit grayscale image. The computer system 1120also comprises an edge locator 1130 and an angle determiner 1135 whichare operationally able to crop the actual x-ray data from the largerpicture such that junk data values along the edge representingnon-exposed portions of the x-ray are removed. Examples of such junkdata values are shown at 705 of FIG. 7A. An X-ray data locator 1140 canthen use one or more of the edge locator 1130 and the angle determiner1135 to locate the x-ray data image within the picture taken by thecharge coupled device 1105. A parameter chooser 1145 is operationallyable to determine parameters that will be used to filter the x-ray dataimage. The specific parameters chosen for a specific image may be based,for example, on such values as the species of the animal being x-rayed,the body part being x-rayed, the specific view of the x-ray, and theenergy setting used for the x-ray. Once the parameter is chosen, aparameter applier 1150 can be used to apply the parameter to the x-rayto produce a parameterized x-ray. A displayer 1155 is also includedwhich allows the parameterized, filtered, x-ray to be displayed. Thex-ray may also be displayed at intermediate stages, such as prior tocropping, and prior to filtering. The displayer may be directlyconnected to the computer system 1120, or may be connected through anetwork link, allowing the x-ray to be displayed remotely.

IX. X-Ray Device Enclosure Unit Embodiments

FIG. 13A is a perspective view of an embodiment of the x-ray deviceenclosure unit 1300, which may be a mirror box 1301. A light measuringdevice (such as the light-measuring device 408 of FIG. 4) such as acamera is mounted at 1303, preferably outside of the x-ray deviceenclosure itself and having a camera opening 1304. The camera opening1304 may optionally be covered by a light-permeable membrane. Thisopening is also shown at 1404 (FIG. 14) and at 1504 (FIG. 15). The topof the enclosure unit may be surrounded by a flange 1302, which, in someembodiments, is filled at the corners and welded to create a continuousflange. The mirror box 1301 (such as the beam enclosure unit 120 atFIG. 1) dissipates sufficient camera heat such that that no otherheat-dissipation device is necessary for the operation of the camera.

FIG. 13B is a plan view of the embodiment of the x-ray device shown inFIG. 13A. A camera box 1306 is shown, which is attached to the sides ofthe mirror box but is otherwise open, so that a camera mounted on cameramount 1303 can be exposed to an x-ray image. A perspective view of theopening between the camera box 1306 and the mirror box 1301 is shown at1365, this view can also be called the aperture. Other views of thecamera opening (or aperture) are shown in FIG. 15 at 1565 and in FIG.16B at 1665. A mirror, such as the mirror 406, can cover all or aportion of the surface shown at 1422. In an exemplary embodiment, thismirror is at a substantially 45 degree angle to the camera opening 1365.In an exemplary embodiment, the dimensions of the mirror box opening1360 is 15.62 inches, with the dimensions at 1355 being 18.62 inches.

FIG. 14 is an exploded perspective view 1400 of the x-ray deviceenclosure unit of FIG. 13A. A screen, such as that shown at 110 in FIG.100 can be mounted within the mirror box 1301 on flanges 1418, 1420which protrude into the center of the box such that substantially alllight is blocked. Mounts 1406, 1412 and 1414, which can be kinematicmounts, can be preferably used to mount a camera or other lightmeasuring device, such as that shown at 408 (FIG. 4) to be focused withminimal parallax and keystoning. In an exemplary embodiment, 27different angles can be adjusted on the mirror box to facilitate camerafocus.

A mirror, such as the mirror 406 (FIG. 4) which can be used to bend thelight path to allow the camera mounted outside the mirror box to capturesubstantially all of the x-ray image, can be mounted on all or a portionof the surfaces shown at 1422. This mirror may be used to at leastpartially produce a folded light path, such that the light imagetraveling along the folded light path is reflected by the mirror, afirst segment of the light image crossing a second segment of the lightimage at least twice, the mirror substantially focusing the light imageon a camera, such as the light-sensing device at 408 (FIG. 4). Anexemplary embodiment of the folded light path is shown at 310 and 315(FIG. 3).

Another exemplary embodiment of the folded light path is shown at 1670and 1671 of FIG. 16C.

A camera box 1415 (such as the camera box 1306 in FIG. 3) is mountedflush with the mirror box 1350 with an aperture (embodiments shown at1365, 1565 and 1665) between them. A mirror 1422 can be mounted atsubstantially a 45 degree angle to this aperture, though other angles ofmounting are envisioned. Additionally, the mirror 1422 may be enhancedby surface preparation to provide additional light reflection whenmounted approximately between 78 degrees and 120 degrees to the incidentlight beam. The mirror 1422 may reflect in excess of 97.5% of theavailable light, and may be aluminum-enhanced, and micro- orpico-ground.

The camera box 1415 has a second mirror mounted on the surface shown at1613 (FIG. 16). This mirror surface 1613, also shown at 1413 (FIGS. 14and 15.) can be mounted at an angle substantially 85 degrees incident tothe mirror box mirror 1422. Additionally, the mirror 1613 may beenhanced by surface preparation to provide additional light reflectionwhen mounted approximately between 45 degrees and 112 degrees to theincident light beam. The mirror 1613 may reflect in excess of 97.5% ofthe available light, and may be aluminum-enhanced, and micro- orpico-ground.

Brackets 1418, 1420 can be used to ensure that a screen, such as thescreen 110 is impervious to light, and that it is mounted securely.

A photon detection device, such as that shown at 414 (FIG. 4), such asan ionization chamber or a proportional gamma ray detector, may bemounted substantially outside of the mirror box; such as in the bracketsshown at 1410.

An opening is shown at 1408 between the photon detection device and themirror box. In an exemplary embodiment, the mirror 406 (FIG. 4) ispermeable to X-rays; and covers the opening 1408 between the photondetection device 414 (FIG. 4) and the mirror box 1301 (FIG. 13). Thephoton detection device 414 (FIG. 4) can be mounted, such as with thebrackets 1410, such that at least a portion of an X-ray image (X-rays105 or light photons 110) strikes the photon detection device 414 (FIG.4) through the mirror 406 (FIG. 4).

FIG. 15 is an exploded perspective view 1500 of the X-ray deviceenclosure unit of FIG. 13A shown from the opposite side of the devicethan that shown in FIG. 14. A bracket 1504 on camera box 1582 is shownwhich can be used to mount a light measuring device, such as the lightmeasuring device 408.

X. Exemplary System Embodiment Showing Mirror Placement and Light Path

FIG. 16A is an elevation view 1600 of another embodiment of an X-raydevice enclosure unit similar to FIG. 13A. Mounting brackets 1410 whichcan be used to hold a photon detection device are shown. In an exemplaryembodiment, the height of the mirror box 1600 is 16.11 inches. Thecamera box (embodiments also shown at 1306, 1415 and 1565) is shown at1615. FIG. 16B is elevation cutaway view 1650 of the X-ray deviceenclosure unit of FIG. 16A.

FIG. 16C shows an exemplary embodiment of a folded light path used, forexample, to allow a light measuring device (such as the light measuringdevice 408 of FIG. 4) positioned outside the path of X-rays (such as theX-rays 105 of FIG. 1) to receive an X-ray image.

FIG. 16C has a first mirror 1622, mounted at substantially a 45 degreeangle to the aperture 1684 located between a mirror box 1669 and acamera box 1682. A second mirror 1613 is located on the inside diagonalsurface of the camera box 1682. A X-ray image enters from the top of thebeam enclosure 120 (FIG. 1), and is converted at least partially intolight photons 115 (FIG. 1). These light photons 115 (FIG. 1) arereflected by the first mirror 1622 to the second mirror 1613. The degreeof the reflection depends upon where along the surface of the mirror thelight photon hits, with photons hitting nearer the bottom of the mirrorreflecting at a more acute angle, such as the angle 1673 formed by theexemplary light segment 1671, than those hitting nearer the top of themirror, such as the angle 1672 formed by the exemplary light segment1670.

When the rays hit the second mirror, they are reflected towards lens ofa light-measuring device 1618. Rays that hit lower on the mirror arereflected at a more obtuse angle, such as the angle 1674 of lightsegment 1671 than those that hit nearer the top of the mirror, such asthe angle 1675 of light segment 1670.

It can be seen that each light ray crosses the path of at least oneother light ray at least twice. The two exemplary light segments in theexample cross, for example, at 1686 and 1688.

XI. Computing Environment

With reference to FIG. 17, an exemplary system for implementing at leastportions of the disclosed technology includes a general purposecomputing device in the form of a conventional computer 1700, which maybe a PC, or a larger system, including a processing unit 1702, a systemmemory 1704, and a system bus 1706 that couples various systemcomponents including the system memory 1704 to the processing unit 1702.The system bus 1706 may be any of several types of bus structures,including a memory bus or memory controller, a peripheral bus, and alocal bus using any of a variety of bus architectures. The system memory1704 includes read only memory (ROM) 1708 and random access memory (RAM)1710. A basic input/output system (BIOS) 1712, containing the basicroutines that help with the transfer of information between elementswithin the computer 1700, is stored in ROM 1708.

The computer 1700 further includes one or more of a hard disk drive 1714for reading from and writing to a hard disk (not shown), a magnetic diskdrive 1716 for reading from or writing to a removable magnetic disk1717, and an optical disk drive 1718 for reading from or writing to aremovable optical disk 1719 (such as a CD-ROM or other optical media).Flash memory (not shown) may also be used to store information. Thesedisks 1714, 1716, 1717, 1718, and 1719, the hard drive and the flashmemory may be used separately or in combination to store digital X-rayimages. Furthermore a cataloging system may also be included to alloweasy retrieval of a desired image.

The hard disk drive 1714, magnetic disk drive 1716, and optical diskdrive 1718 (if included) are connected to the system bus 1706 by a harddisk drive interface 1720, a magnetic disk drive interface 1722, and anoptical drive interface 1724, respectively. The drives and theirassociated computer-readable media provide nonvolatile storage ofcomputer-readable instructions, data structures, program modules, andother data for the computer 1700. They may also be used to storealgorithms used to process, store, and retrieve the digital images, andsoftware to process the radiation information received from light orradiation detector, to, for example, determine if an X-ray image hasbeen received. Further, they may also be used to store other algorithmsused in conjunction with the digital X-ray images. Other types ofcomputer-readable media which can store data that is accessible by acomputer, such as magnetic cassettes, flash memory cards, digital videodisks, CDs, DVDs, RAMs, ROMs, and the like (none of which are shown),may also be used in the exemplary operating environment.

A number of program modules may be stored on the hard disk 1714,magnetic disk 1717, optical disk 1719, ROM 1708, or RAM 1710, includingan operating system 1730, one or more application programs 1732,including applications to manipulate, store, transfer, etc. the digitalX-ray images, other program modules 1734, and program data 1736. A usermay enter commands and information into the computer 1700 through inputdevices, such as a keyboard 1740 and pointing device 1742 (such as amouse). Other input devices (not shown) may include a digital camera,microphone, joystick, game pad, satellite dish, scanner, or the like(also not shown). These and other input devices are often connected tothe processing unit 1702 through a serial port interface 1744 that iscoupled to the system bus 1706, but may be connected by otherinterfaces, such as a parallel port, game port, or universal serial bus(USB) (none of which are shown). A monitor 1746 or other type of displaydevice is also connected to the system bus 1706 via an interface, suchas a video adapter 1748. This monitor 1746 may be used to display thedigital X-ray images. Other peripheral output devices, such as speakersand printers (not shown), may be included.

The computer 1700 may operate in a networked environment using logicalconnections to one or more remote computers 1750, and to aremote-triggered X-ray imaging system as shown, for example, in FIG. 1.The remote computer 1750 may be another computer, a server, a router, anetwork PC, or a peer device or other common network node, and typicallyincludes many or all of the elements described above relative to thecomputer 1700, although only a memory storage device 1752 has beenillustrated in FIG. 17. The logical connections depicted in FIG. 17include a local area network (LAN) 1754 and a wide area network (WAN)1756. Such networking environments are commonplace in offices,enterprise-wide computer networks, intranets, and the Internet.

When used in a LAN networking environment, the computer 1700 isconnected to the LAN 1754 through a network interface 1758. When used ina WAN networking environment, the computer 1700 typically includes amodem 1760 or other means for establishing communications over the WAN1756, such as the Internet. The connection may be a wireless connection.The modem 1760, which may be internal or external, is connected to thesystem bus 1706 via the serial port interface 1744. In a networkedenvironment, program modules depicted relative to the computer 1700, orportions thereof, may be stored in the remote memory storage device1752. Digital X-ray images may also be stored in the remote memorystorage device 1752. The network connections shown are exemplary, andother means of establishing a communications link between the computersmay be used.

XII. Exemplary Gamma Ray Detection and X-ray Recording

FIG. 18 shows an exemplary method 1800 for choosing whether to discardor save an image after gamma radiation has been detected. At 1805, agamma ray detector, such as the photon detection device 414 shown inFIG. 4, registers a detection event corresponding to detected gammaradiation having a magnitude greater than a predetermined thresholdvalue. In an exemplary system, a detection event will not be recorded ifthe detected gamma radiation has a magnitude less than a thresholdvalue—the trigger detection value. The specific threshold size forrepresentative embodiments may be X-ray source specific, as differentX-ray sources produce X-ray radiation of different intensities orenergies. As a general rule, the trigger detection value should be setlow enough to ensure that an actual X-ray pulse is detected by thetrigger, but high enough that stray background radiation that would notreasonably be an X-ray pulse does not trigger a detection event. Forexample and without limitation, an exemplary threshold for the detectionevent trigger may be 0.1 volt when the X-ray pulse produces anassociated electrical signal of about 0.12 volts. In differentembodiments, thresholds can correspond to a higher or lower percentageof the associated X-ray voltage. A different X-ray system may have X-raypulses with higher energy, and so for that system, a reasonabledetection event trigger may be 0.3 volts. Other systems may havedetection triggers between 1 volt and 0.3 volts, or may have detectiontriggers with other values.

At 1810, a camera, such as an image sensor associated with acharge-coupled device or other image sensor begins recordingsubstantially as soon as the detection event is registered.

Once a detection event has been registered, the gamma ray detectorcontinues to provide radiation values. These values are then scrutinizedover a period of time to determine if an actual X-ray event hasoccurred, as opposed to background radiation triggering the detectionevent. In other examples, X-rays are detected with a photodetectorconfigured to detect ultraviolet, visible, or infrared light emitted byan X-ray to light converter. Such a photodetector produces an electricalsignal that can be evaluated to detect a modulation corresponding to anX-ray beam modulated to identify X-ray radiation from the X-ray source.Threshold detection can also be used.

One way to determine if an X-ray has occurred is by deciding if X-raypulses have been generated. Typical X-ray sources produces X-ray burststhat includes X-ray pulses that can be used to generate a single X-rayimage. The pulses have an intensity associated with a detected voltage,and a duration. At 1815, it is determined if the detection event wasnoise or if it indicated the beginning of an X-ray event. To do so, asshown in more detail in FIG. 20, in an exemplary embodiment, anelectrical signal from the gamma ray detection is analyzed to determineif one or more recognizable pulses occurred within a given time frame.Such analysis may be done, for example by an X-ray analyzer in software,associated with a computer that is coupled to a camera and the gamma raydetector. Other embodiments may locate the X-ray analyzer elsewhere.

If it is determined that no actual X-ray event occurred (e.g., that thedetector was triggered by ambient noise), then, at 1820, the cameraimage is flushed. In some embodiments, prior to the flush, the image maybe recorded for, e.g., quality control, testing, or other purposes. If,at 1815, it is determined that an actual X-ray was taken (e.g., one ormore pulses was sensed), then the camera continues recording the imagefor a predetermined period of time 1825. In an exemplary embodiment, thepredetermined period extends beyond the actual X-ray generation time,and is sufficiently long to receive the light for a substantial portionof a phosphor screen. This ensures that the bulk of the available lightis captured, producing a high quality X-ray image. In some embodiments,the camera records for a predetermined time after it is determined thatthe detected gamma radiation is from an actual X-ray generation 1815. Inother exemplary embodiments, the camera substantially always records theimage, whether triggered by noise or an actual X-ray event, for the samepredetermined time. In an exemplary embodiment, the camera valuesconfigured to detect a light flux for 0.5 seconds from triggering.

After the predetermined time, if the image is determined to not havebeen triggered by noise, the recorded X-ray image is saved 1830 to amemory and/or a hard drive and, optionally, displayed.

At 1815, to determine if X-ray radiation from the X-ray source ispresent, the gamma ray detector continues to record the intensity of thegamma rays inside the X-ray capture device. In an exemplary embodiment,if it is determined that at least some number of pulses with a firstthreshold intensity and/or a second threshold duration have not occurredwithin a threshold time, then the original trigger is assumed to be thespurious, and the camera image, which began recording at or near theinitial trigger, is flushed. The device then returns to a waiting state.

In another exemplary embodiment, if it is determined that a single pulsewith a first threshold intensity and/or a second threshold duration havenot occurred within a threshold time, then it is determined that theoriginal trigger was spurious, and the camera image, which beganrecording at the initial trigger, is flushed. In yet another exemplaryembodiment, two pulses are compared to each other; if it is determinedthat they share a similar intensity and/or duration, then the image isdetermined to be an X-ray image associated with exposure to X-rays fromthe X-ray source, and the image is preserved.

The number of pulses needed to determine if an X-ray imaging event hasoccurred, and other associated thresholds which may be used, such as aduration threshold, an intensity threshold, the predetermined camerarecording time, and so forth, may be dependent on a number of factors,including if the X-ray burst temporal waveform corresponds to ahalf-wave rectified or full-wave rectified waveform, and other specificfeatures of any given X-ray burst, if the X-ray burst corresponds to athree-phase waveform, and if so, if 6 pulses, 12 pulses, or other numberof X-ray pulses are included in a burst. Similarly, as another example,half-wave rectified X-ray pulses are produced, generally, at 60 pulsesper second, while full wave rectified X-ray pulses are typicallyproduced at 120 pulses per second, resulting in potentially differentthresholds.

In another exemplary embodiment, the gamma radiation profile 1900 (FIG.19) is examined for a given time, such as the predetermined camerarecording time (1905-1910, FIG. 19), to determine, without one or morepredefined pulse, duration, or intensity thresholds, if the patternappears to be that made by an X-ray burst from the X-ray source. Thus,if some number of similarly sized and similarly spaced pulses appear,then the image is deemed to be an actual X-ray image of a specimen.

FIG. 19 is a chart representing the gamma radiation generated forproducing an X-ray image, and the associated camera recordation time. AnX-ray burst generated by a representative X-ray source comprises adiscrete number of X-ray pulses. The X-ray burst illustrated in FIG. 19has four pulses 1920, 1925, 1930, 1940. Each pulse has a duration and anintensity that is the electrical energy radiation value of the pulse. Ascan be seen, both the duration and the intensity may not be constantvalues; thus measurements concerning them may need to take high values,average values or use other methods to determine reasonable values. Thebaseline gamma radiation intensity 1955, may not record as a straightzero value, as seen here, due to ambient noise. The intensity, in anexemplary system, is the absolute value of the energy, not a measurementfrom the possibly unstable baseline. The pulses, if from an X-raysource, should also be substantially evenly spaced, such as the spaceindicated by 1940, which in this example, is about 4 ms.

At 1915, the gamma detector records a detection event. Then, at 1905,the camera (e.g., 408 in FIG. 4) begins recording. The lines 1905,1910indicates that the camera is recording an image. Notice that there maybe a lag, the latency period, between the first gamma ray registered1915 and when the camera begins recording 1905. In this case, thelatency period is about 4 ms.

The camera continues recording for some time 1960 past the last X-raypulse 1935 to capture a significant portion of the available light onthe still-glowing scintillator screen that remains after the X-raysthemselves have stopped. In the embodiment shown, the camera records forapproximately 0.4 seconds. Other embodiments may record for longerperiods of time, such as 0.5 sec, or for shorter periods of time,depending, in some embodiments, on one or more of a multitude of factorsincluding the intensity of the X-ray beam, the type of scintillatorscreen used, and so on.

FIG. 20 at 2000 is a flowchart describing an exemplary method todetermine if an actual X-ray has been recorded, one possiblecontinuation of the process shown at 1815 in FIG. 18. The camera (whichmay be a CCD camera) began recording an image shortly after a gamma rayof sufficient intensity was received as shown at 1810 in FIG. 18, andillustrated at 1905 in FIG. 19. The system now determines if an actualX-ray photograph has been generated, or if the radiation event thattriggered the initial recording (at 1810) was due to ambient noise.

In an exemplary embodiment, at 2005, the camera continues gathering dataand the gamma detector continues recording the gamma radiation valuesreceived. At 2010, the system waits for a time, which may be apredetermined time. The time to wait is, to a certain extent, systemdependent, but should be long enough to determine if, at a minimum, apulse has occurred. Other embodiments wait for enough time for more,such as two, pulses. In some systems, the time to wait is the total timethe camera will use to record the (supposed) X-ray image, that is, theX-ray generation time plus some extra time; the time necessary for thecamera to accurately and/or effectively record some, all (or essentiallyall) of the light that the X-ray generates by way of the glowingscintillator screen.

At 2020, it is determined, in an exemplary embodiment, if at least tworecognizable X-ray pulses have occurred. In some systems, locating twopulses may be sufficient, in other systems, between 1 and 12 pulses mayneed to be located to determine that an accurate X-ray exposure hasoccurred.

At 2025, if it is determined at 2020 that two pulses (in someembodiments) or somewhere between one and twelve pulses (in otherembodiments) have not occurred, than the image being recorded by thecamera (e.g., light measuring device 408 in FIG. 4) is discarded, andthe system waits for the next gamma detection event.

At 2030, if it is determined that at least two pulses (depending on theembodiment) have occurred, then the system, in some embodiments, waitsfor a second predetermined time to ensure that all (or almost all)available light is accumulated by the camera.

At 2035, the image recorded by the camera 408 is saved to some medium,e.g., a computer screen, film, and/or a hard drive, or some otherstorage device.

FIG. 21 at 2100 is a flowchart describing an exemplary method todetermine if at least a single pulse has been recorded, a continuationof the process shown at 2020 in FIG. 20. It is understood by those ofskill in the art that this method can be repeated any number of times todetermine if multiple pulses have occurred. At 2102, pulse data isanalyzed, and separated into pulses. At optional 2105 it is determinedif a pulse has a threshold dwell time. This threshold time may bepredetermined, or the individual pulses dwell times may need to bewithin some known percentage of each other, over a minimum thresholdtime, determinable on the fly. If so, then the process continues (insome embodiments) at 2115. In other embodiments, the gamma radiation isdetermined to be a pulse.

If it is determined that the pulse does not have the threshold dwelltime, then at 2110, it is determined that the gamma radiation event isnot an X-ray pulse.

At optional 2115, it is determined if a pulse has a threshold intensity.That is, each pulse should spend some percentage of time over or at aminimum voltage. As can be seen from the pulses 1920, 1925, 1930, 1935of FIG. 19, the pulses are not steady, but instead are composedthemselves of a number of smaller pulses. Hence, the pulses aregenerally not expected to stay at the minimum voltage for the entiredwell time. If the pulse or pulses are not at the threshold intensity,then at 2120, it is determined that the gamma radiation event is not anX-ray pulse. If they are at the threshold intensity, then the processcontinues (in some embodiments) at 2125. In other embodiments, the gammaradiation is determined to be a pulse.

At optional 2125, and if there are more than two pulses, it isdetermined if the spacing between pulses is within some threshold. Ifnot, then at 2130, it is determined that the gamma radiation event isnot an X-ray pulse. If so, at 2135, the gamma radiation is determined tobe a pulse.

XIV. Alternatives

Having described and illustrated the principles of our variousembodiments with reference to the illustrated embodiments, it will berecognized that the illustrated embodiments can be modified inarrangement and detail without departing from such principles.

Examples of object sizes, relative ratios between parts, angles shown,etc., are examples only and can be modified appropriately. Also, thetechnologies from any example can be combined with the technologiesdescribed in any one or more of the other examples.

In view of the many possible embodiments, it should be recognized thatthe illustrated embodiments are examples only and should not be taken asa limitation on scope. For instance, various components of systems andmethods described herein may be combined in function and use. Wetherefore claim as our invention all subject matter that comes withinthe scope and spirit of these claims.

1. A system comprising: an X-ray to light converter which converts anx-ray image to a light image; a mirror box with a camera opening; afirst mirror mounted within the mirror box; a second mirror mountedwithin the mirror box; a light measuring device mounted substantiallyoutside of the mirror box behind the camera opening; a gamma raydetector which detects gamma rays over a first threshold; a ccd cameramounted substantially outside of the mirror box behind the cameraopening and operationally able to begin recording the light imagesubstantially when the gamma ray detector detects the gamma rays overthe first threshold; an X-ray analyzer operationally able to determineif gamma rays detected by the gamma ray detector form one or morerecognizable X-ray pulses occurring within a given time frame, and ifso, operationally able to determine that the gamma rays detected arefrom an X-ray generator; a recorded image saver operationally able tosave the light image if the gamma rays detected are from an X-raygenerator; wherein the first and second mirrors are arranged such that afolded light path is created such that a first segment of the lightimage crosses a second segment of the light image, the mirrorssubstantially transmitting the light image to the ccd camera.
 2. Thesystem of claim 1 further comprising a light image flusher operationallyable to flush the light image from the ccd camera if the X-ray analyzerdetermines that the gamma rays detected are not from an X-ray generator.3. The system of claim 1 wherein the gamma ray detector is substantiallyoutside of the mirror box; there being an opening between the gamma raydetector and the mirror box.
 4. The system of claim 1 wherein the firstmirror is permeable to X-rays; wherein the first mirror covers theopening between the gamma ray detector and the mirror box; and whereinthe gamma ray detector is mounted such that at least a portion of theX-ray image strikes the gamma ray detector through the mirror.
 5. Thesystem of claim 1 wherein the ccd camera is operationally able to recordthe light image for a predefined period after the X-ray generator hasceased generating X-rays.
 6. The system of claim 1 wherein the ccdcamera is operationally able to record the light image for 0.5 seconds.7. The system of claim 1 wherein the X-ray analyzer is operationallyable to determine if at least one pulse has spent some percentage oftime over a minimum voltage.
 8. The system of claim 7 wherein the X-rayanalyzer is operationally able to determine if at least one recognizablepulse has been detected by being operationally able to determine thedwell time of measured radiation between a pulse start and a pulse stop.9. The system of claim 1 wherein the X-ray analyzer is operationallyable to determine if at least one recognizable pulse has been detectedby being operationally able to determine the intensity of measuredradiation between a pulse start and a pulse stop.
 10. The system ofclaim 1 wherein the X-ray analyzer being operationally able to determineable to determine if at least three recognizable pulses have beendetected comprises being operationally able to determine if a firstspacing between a first and second pulse and a second spacing betweenthe second and a third pulse is within a predetermined percentage. 11.The system of claim 7 wherein the X-ray analyzer is operationally ableto determine if the gamma ray detector has detected at least fourpulses.
 12. The system of claim 1 wherein the X-ray analyzer comprisessoftware useable to analyze gamma radiation, the software associatedwith a computer system linked to the ccd camera and the gamma detector.13. A system comprising: an x-ray to light converter which converts anx-ray image to a light image; a mirror box with a camera opening andgamma ray detector opening; a mirror mounted within the mirror box overgamma ray detector opening; a camera mounted substantially outside ofthe mirror box above the camera opening; and an gamma ray detectormounted substantially outside the mirror box behind the gamma raydetector opening; the gamma ray detector operationally able to triggerthe camera to produce an recording of at least a portion of the lightimage when a threshold amount of X-ray radiation is detected by thegamma ray detector; wherein the mirror is permeable to x-rays; andwherein the gamma ray detector is mounted such that at least a portionof the x-ray image strikes the gamma ray detector; and wherein if atleast two x-ray pulses are detected by the gamma ray detector within apredetermined time than the camera is operationally able to record therecording of the at least a portion of the light image to a recordingmedium.
 14. The system of claim 13 wherein if at least two x-ray pulsesare not detected by the gamma ray detector within a predetermined timethan the camera is operationally able to flush the recording of the atleast a portion of the light image.
 15. The system of claim 13 thepredetermined time that the camera records the at least a portion of thelight image extends beyond the time that an X-ray generator generatesx-rays to generate the X-ray image.
 16. A method of generating an X-rayimage, comprising: converting at least some X-ray photons generated froman X-ray source to light photons; triggering a gamma ray sensor when thegamma ray sensor detects X-ray photons in an amount greater than athreshold amount; using a first mirror to reflect the light path suchthat substantially all of the light photons are reflected towards a ccdcamera, the ccd camera beginning recording the light substantially whenthe gamma ray sensor is triggered; the ccd camera continuing to recordthe light for a predetermined time to produce an X-ray image; andrecording the X-ray image to a storage medium only if the gamma raysensor senses at least two X-ray pulses within a predetermined time. 17.The method of claim 16 wherein the ccd camera records the light tocreate the X-ray image for a predetermined time after the X-ray sourcehas ceased generating X-rays.
 18. The method of claim 16 wherein the ccdcamera records the light for 0.5 seconds.
 19. The method of claim 16wherein the ccd camera destroys the X-ray image if the gamma ray sensordoes not sense at least two pulses within the predetermined time.
 20. Atangible computer readable medium comprising computer-executableinstructions for performing the method of claim 16.